Low-e coating with high visible transmission

ABSTRACT

Coated articles are provided with an anti-reflection system(s) which enables high visible transmission and/or low visible reflection. Neutral color is also achievable in certain example embodiments. In certain example embodiments, the anti-reflection system(s) is used in conjunction with a double silver (Ag) layer stack which provides low sheet resistance and/or emissivity.

RELATED APPLICATION

This application is a Divisional of application Ser. No. 10/024,613,filed Dec. 21, 2001 now U.S. Pat. No. 6,830,817, which is related toU.S. patent application Ser. No. 09/794,224, filed Feb. 28, 2001 (nowU.S. Patent No. 6,576,349), the entire contents of which are herebyincorporated by reference in this application.

BACKGROUND AND SUMMARY OF THE INVENTION

The Ser. No. 09/794,224 application discloses coated articles having thefollowing layer stack, as shown in FIG. 1 herein, from the glasssubstrate outwardly:

TABLE 1 Example Materials/Thicknesses Layer Substrate (1–10 mm)Preferred Range ({acute over (Å)}) More Preferred ({acute over (Å)})Example (Å) TiO₂ 0–400 {acute over (Å)} 50–250 {acute over (Å)} 100 ÅSi_(x)N_(y) 0–400 {acute over (Å)} 50–250 {acute over (Å)} 170 ÅNiCrO_(x) 5–100 {acute over (Å)} 10–50 {acute over (Å)} 18 Å Ag 50–250{acute over (Å)} 80–120 {acute over (Å)} 105 Å NiCrO_(x) 5–100 {acuteover (Å)} 10–50 {acute over (Å)} 16 Å SnO₂ 0–800 Å 500–850 Å 650 ÅSi_(x)N_(y) 0–800 {acute over (Å)} 50–250 {acute over (Å)} 170 ÅNiCrO_(x) 5–100 {acute over (Å)} 10–50 {acute over (Å)} 18 Å Ag 50–250{acute over (Å)} 80–120 {acute over (Å)} 105 Å NiCrO_(x) 5–100 {acuteover (Å)} 10–50 {acute over (Å)} 16 Å SnO₂ 0–500 Å 100–300 Å 150 Å Si₃N₄0–500 {acute over (Å)} 100–300 {acute over (Å)} 250 Å

In other embodiments of Ser. No. 09/794,224, the bottom titanium oxidelayer may be removed or replaced with a silicon nitride layer.

While the aforesaid coated articles described in the Ser. No. 09/794,224application provide good color, and good ultraviolet (UV) and/orinfrared (IR) reflection, increased visible transmission and/or reducedvisible reflection would sometimes be desirable.

Neutral color is also desirable for coated articles in certainapplications. Many conventional methods of making color of a coatedarticle more neutral result in decreased visible transmission and/orincreased visible reflection. Heretofore, it has been difficult toincrease visible transmission and reduce visible reflection, while atthe same time providing or maintaining rather neutral color andsatisfactory solar control or thermal characteristics. Whether a coloris “neutral” or not is subjective, and is a function of personal taste.However, generally speaking, color moving toward a neutral color target(e.g., a*=0, b*=0, or some other neutral color target such astransmissive a*=−2 and transmissive b*=−3.4) is desired, although suchtargets do not have to be met in all embodiments of this invention.

In view of the above, it is an object of certain embodiments of thisinvention to provide a solar controlling coated article (i.e., anarticle including at least one and preferably two or more layers such asAg and/or Au for reflecting IR and/or TV) having increased visibletransmission and/or reduced visible reflectance. In certain examplenon-limiting embodiments of this invention, it is an object to combinesuch high visible transmission and/or reduced visible reflection withneutral color of the coated article. Alternatively, the use of animproved anti-reflection layer(s) system(s) may enable coatings to haveor utilize more robust contact layer(s) (e.g., thicker for betterdurability) and/or thicker silver (Ag) layer(s) (i.e., improved thermalperformance) while maintaining similar transmission characteristics ifincreased transmission is not a most desired feature (e.g., ifdurability is a most desired feature).

Another object of this invention is to fulfill one or more of theabove-listed objects and/or needs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a coated article according to anembodiment of this invention, as disclosed in the Ser. No. 09/794,224application.

FIG. 2 is a cross sectional view of a coated article according to anembodiment of this invention.

FIG. 3 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 4 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 5 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 6 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 7 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 8 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 9 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 10 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 11 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 12 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 13 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 14 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 15 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 16 is a cross sectional view of a coated article according toanother embodiment of this invention.

FIG. 17 is a cross sectional view of a coated article according toanother embodiment of this invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

The instant invention relates to coated articles which may be used inapplications including but not limited to insulating glass (IG) windowunits, monolithic windows, skylight windows, and/or any other type ofwindow. Coated articles according to this invention include an improvedanti-reflection layer(s) system for reducing visible reflectance and/orincreasing visible transmission in coated articles that provide solarcontrol (e.g., IR and/or UV reflection) functionality. Surprisingly, incertain example embodiments it has been found that certainanti-reflection layer(s) systems of the instant invention can both: (a)improve visible transmission and/or reduce visible reflectance, while atthe same time (b) achieving an acceptable neutral color of the resultingcoated article.

FIG. 2 is a cross sectional view of a coated article according to anembodiment of this invention. The coated article of FIG. 2, like allother coated articles herein, may be used in any of the aforesaidapplications (e.g., architectural windows, etc.). The coated article ofFIG. 2 includes from the glass substrate outwardly (all indices ofrefraction “n” at 550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

As shown in FIG. 2, the contact layers (i.e., NiCrO_(x) layers) surroundand contact the IR reflecting Ag layers. The NiCrO_(x) layers herein arecalled “contact” layers because they each contact an IR reflecting layer(i.e., an Ag layer). The NiCrO_(x) contact layers provide the mostimmediate chemical protection for the Ag layer, and also serve asadhesion and/or nucleation layers. The contact layers may or may not beoxidation graded as described in the Ser. No. 09/794,224 application, indifferent embodiments of this invention. Moreover, instead of NiCrO_(x),one or more of the contact layers may be of or include other material(s)including but not limited to NiCr, NiCrN_(x), NiCrO_(x)N_(y), ZnO,Al₂O₃, TiO₂, ZnAlO_(x), Ni, Cr, CrN_(x), NiO_(x), NbO_(x), anycombination thereof, and/or the like. Moreover, in any embodimentherein, materials such as titanium oxide or niobium oxide could evenserve as top contact layers (i.e., above Ag layer(s)), in addition todielectrics herein. Example thicknesses of the contact layers, and otherlayers herein, are discussed above in the Background and Summary sectionof this application. The above applies to contact layers in the FIGS.1–17 embodiments.

Instead of Ag, other metallic IR reflecting materials (e.g., Au, Agalloys, Au alloys, etc.) may be used for one or more of the IRreflecting layers (this applies to the FIGS. 1–17 embodiments). Thethickness of the metallic Ag layers (IR reflecting layers) is chosen inorder to achieve the desired thermal performance (see example thicknessranges above). For example, the Ag layer may be from about 50–250 Åthick, in order to achieve sheet resistance (R_(s)) (before and/or afterheat treatment) of less than or equal to 10.0 ohms/square, morepreferably less than or equal to 8.0 ohms/square, even more preferablyless than or equal to 5.0 ohms/square, and most preferably less than orequal to 4.0 ohms/square. In a similar manner, the Ag layer(s)thickness(es) are chosen so that the coating (or coated article) has anormal emissivity (E_(n)) of no greater than 0.08, more preferably nogreater than 0.06, and most preferably no greater than 0.05 (beforeand/or after heat treatment). The aforesaid emissivity and sheetresistance characteristics apply to the FIGS. 1–17 embodiments.

The IR reflecting and contact layers of the FIG. 2 coating (and theFIGS. 3–17 coatings) are discussed in the Ser. No. 09/794,224application (incorporated herein by reference), and are not discussedherein for reasons of simplicity. See the thicknesses/materialsdescribed in the Ser. No. 09/794,224 in this regard. The focus hereinlies with the provision of dielectric layers which are utilized in orderto: (a) increase visible transmission, (b) decrease visible reflection(e.g., glass side), and/or (c) provide neutral color. With respect tothe FIG. 2 embodiment in particular, it will be shown below that thedielectric layers used therein (compared to in FIG. 1) result in asignificant increase in visible transmission combined with a decrease invisible reflectance (glass and/or film side). This is beneficial.

It can be seen that the FIG. 2 embodiment of this invention differs fromFIG. 1 in that (a) the bottom silicon nitride layer from FIG. 1 has beenremoved, (b) a titanium oxide layer has been added in the middle portionM, (c) the middle silicon nitride layer from FIG. 1 has been removed,(d) titanium oxide and silicon oxide layers have been added to the topportion T of the coating in FIG. 2, and (e) the top silicon nitridelayer from FIG. 1 has been removed. By using silicon oxide (i.e.,stoichiometric SiO₂, or alternatively a non-stoichiometric form) overthe top tin oxide layer, and by utilizing the titanium oxide (i.e.,stoichiometric TiO₂, or alternatively a non-stoichiometric form such asTiO_(1.50-1.99)) layers as illustrated, the coating (layer system) canbe characterized by the top dielectric portion T having an effectiveindex of refraction n less than that of middle dielectric portion M,which in turn has an effective index of refraction n less than that ofthe bottom dielectric portion B (see FIG. 2). In other words,n_(T)<n_(M)<n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T, n_(M) is the effective index of refractionof the middle dielectric portion M, and n_(B) is the effective index ofrefraction of the bottom dielectric portion B (the “effective” index maybe calculated as a weighted average of the portion, or by any othersuitable technique/method). As shown in FIG. 2, each of the top, middleand bottom dielectric portions T, M and B, respectively, can include aplurality of different dielectric layers, although in alternativeembodiments any or all of these portions need only include a singledielectric layer.

By gradually decreasing the respective effective indices of refraction“n” from the innermost or bottom dielectric portion B, to the middledielectric portion M, and on to the top dielectric portion T toward theair, the anti-reflection system of FIG. 2 enables increased visibletransmission and/or reduced visible reflection to be achieved.Surprisingly, as will be shown below in the Examples of this embodiment,the anti-reflection system also enables fairly neutral color of thecoated article. Moreover, in certain example embodiments of thisinvention, n_(T)<=2.0. The silicon oxide layers herein may be from about10–700 Å thick in certain example embodiments of this invention, morepreferably from 20–600 Å thick, and most preferably from 50–500 Å thick.Upper tin oxide layers herein (i.e., in top portion T above the top IRreflecting layer) may be from about 10–700 Å thick in certain exampleembodiments of this invention, more preferably from 20–600 Å thick, andmost preferably from 40–400 Å thick. Upper titanium oxide layers herein(i.e., in top portion T above the top IR reflecting layer) may be fromabout 10–500 Å thick in certain example embodiments of this invention,more preferably from 40–300 Å thick. Middle titanium oxide layers herein(i.e., in middle portion M between the IR reflecting layers) may be fromabout 10–900 Å thick in certain example embodiments of this invention,more preferably from 50–700 Å thick. Bottom titanium oxide layers herein(i.e., in bottom portion B below the lower IR reflecting layer) may havethicknesses as discussed in Ser. No. 09/794,224.

As with all embodiments herein, the illustrated layers are preferablydeposited/formed via sputtering (see the Examples in the Ser. No.09/794,224 application), although other deposition techniques maycertainly be used in alternative embodiments of this invention.

EXAMPLE(S) OF FIG. 2 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 2 embodiment, whichare to be compared to a Comparative Example(s) (CE) similar to FIG. 1 ofthe instant application. Thus, the CE relates to a coating that issimilar to that illustrated in the Ser. No. 09/794,224 application. Forthe simulation examples herein, the following indices of refraction wereassumed at 550 nm: for glass, n=1.51; for Si₃N₄, n=2.0; forSiO_(x)N_(y), n=1.72; for SiO₂, n=1.45; for SnO₂, n=2.0; for Nb₂O₅,n=2.33; for SiZrN_(x), n=2.32; and for TiO₂, n=2.57 (note: approximatelystoichiometric titanium oxide was assumed in all simulations herein).The thicknesses for each of the layers in the First Table below are inangstroms (Å). The Second Table below sets forth the opticalcharacteristics (e.g., visible transmission, color, etc.) for theExample(s) and CE based upon being annealed and in monolithic form. Allglass substrates were the same with respect to thickness and color. Thetotal dielectric parameter simply adds up the total thickness of alldielectric layers in the coating (i.e., does not include Ag or NiCrO_(x)layers).

It is noted that the examples and comparative examples (CEs) hereinutilized more oxided NiCrO_(x) layers than did the examples in the Ser.No. 09/794,224 application (this explains why the comparative examplesherein, in monolithic non-heat-treated form, have higher visibletransmission than monolithic non-heat treated products in the Ser. No.09/794,224). However, this distinction is not relevant because allNiCrO_(x) layers herein were assumed to have the same amount ofoxidation, so that the comparisons herein between the CEs and theExamples are consistent. It is also noted that the indices for all Agand NiCrO_(x) layers are assumed to be the same for all such layers inthe Examples and the CEs herein. For optical performance (e.g., visibletransmission), each of the parameters in the tables below is withrespect to Ill. C, 2 degree observer. No example herein was consideredheat treated.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 2 embodiment) Glass CEEx. 1 TiO₂ 125 Å 285 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 ÅNiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 615 Å SnO₂ 672 Å 7 Å Si₃N₄ 165 Å 0 ÅNiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 230 Å SnO₂227 Å 45 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å 0 Å SiO₂ 0 Å 380 Å Totaldiel: 1606 Å 1562 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 2 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 79.2% −0.7 −0.8 4.7% 4.6 −4.9 3.8% 3.3 −2.3 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 2 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased transmission T_(vis) %, Ill. C, 2 deg.), but also reducedreflection (e.g., lower glass side reflection and/or film sidereflection). Moreover, fairly neutral transmissive color is alsoprovided. Surprisingly, it can be seen that the FIG. 2 embodimentprovides more neutral color (e.g., transmissive a* and glass sidereflective) than does the CE. In particular, Example 1 (see FIG. 2) hadbetter visible transmission (higher T_(vis)) and better glass and/orfilm side reflection (lower R_(g) and/or R_(f)), and more neutraltransmissive a*, glass side reflective a*, b* color than the ComparativeExample (CE).

FIG. 3 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 3 embodiment differs fromthe FIG. 2 embodiment in that the top dielectric portion T includes onlya silicon nitride layer (stoichiometric Si₃N₄, or alternative anon-stoichiometric type of silicon nitride such as but not limited to aSi-rich type). The FIG. 3 embodiment differs from FIG. 1 (i.e., from theCE) in that (a) the bottom silicon nitride layer from FIG. 1 has beenremoved, (b) a titanium oxide layer has been added in the middle portionM, (c) the middle silicon nitride layer from FIG. 1 has been removed,and (d) the top tin oxide layer from FIG. 1 has been removed. As withall other embodiments herein which use titanium oxide, unless otherwisestated, the titanium oxide may be stoichiometric TiO₂, or alternativelya non-stoichiometric form such as TiO_(1.50-1.99). Likewise, as with allother embodiments herein which use silicon nitride, unless otherwisestated the silicon nitride may be stoichiometric (Si₃N₄) ornon-stoichiometric (e.g., Si-rich). The coated article of FIG. 3includes from the glass substrate outwardly (all indices n at 550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   air (n=1.0)

By using the silicon nitride over the top contact layer in the topdielectric portion T, and the higher index titanium oxide in the middleM and bottom B portion (diluted with the tin oxide in the middle portionM), the layer system can be characterized by the top dielectric portionT having an effective index of refraction n less than that of middledielectric portion M, which in turn has an effective index of refractionn less than that of the bottom dielectric portion B. In other words,n_(T)<n_(M)<n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T (i.e., of the silicon nitride layer in thisembodiment), n_(M) is the effective index of refraction of the middledielectric portion M (i.e., of the tin oxide and titanium oxide layersin this embodiment), and n_(B) is the effective index of refraction ofthe bottom dielectric portion B (i.e., of the titanium oxide layer inthis embodiment). Each of the top, middle and bottom dielectric portionsT, M and B, respectively, can include a plurality of differentdielectric layers, although in alternative embodiments any or all ofthese portions need only include a single dielectric layer (e.g.portions B and T in this FIG. 3 embodiment). By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of FIG. 3 enables increased visible transmission to be achieved.The term “effective” means the overall effective index n in a particularportion B, T or M, regardless of how many dielectric layers are providedtherein. The anti-reflection system may also enable fairly neutral colorof the coated article in certain example embodiments. The siliconnitride layer in portion T may be from about 10–900 Å thick in certainexample embodiments of this invention, more preferably from 20–600 Åthick, and most preferably from 50–500 Å thick.

EXAMPLE(S) OF FIG. 3 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 3 embodiment, comparedto a Comparative Example(s) (CE) similar to FIG. 1 of the instantapplication. Thus, the CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 3 embodiment) Glass CEEx. 1 TiO₂ 125 Å 276 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 ÅNiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 496 Å SnO₂ 672 Å 112 Å Si₃N₄ 165 Å 0 ÅNiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 0 Å SnO₂227 Å 0 Å Si₃N₄ 252 Å 420 Å SiO_(x)N_(y) 0 Å 0 Å SiO₂ 0 Å 0 Å Totaldiel: 1606 Å 1304 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 3 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.8% −0.8 −0.4 4.5% 3.9 −5.0 3.3% 3.3 −2.3 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 3 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 3) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, the Example 1 of this embodiment also had more neutralcolor than the CE with respect to transmissive a*, and particularly withrespect to glass side reflective a*, b*.

FIG. 4 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 4 embodiment differs fromthe FIG. 2 embodiment in that an additional silicon nitride layer hasbeen added in the bottom dielectric portion B between the lower contactlayer and the titanium oxide layer. The term “between” as used herein tostate that a layer(s) is “between” layers x and y does not mean that thelayer(s) contacts layer x or layer y; it merely means that the layer(s)is between the layers x and y regardless of whether other layer(s) arealso between layers x and y. The coated article of FIG. 4 includes fromthe glass substrate outwardly (all indices n at 550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the silicon oxide, tin oxide, titanium oxide and siliconnitride dielectric layers as shown in this embodiment, the layer systemcan be characterized by the top dielectric portion T having an effectiveindex of refraction n less than that of middle dielectric portion M,which in turn has an effective index of refraction n less than that ofthe bottom dielectric portion B. In other words, n_(T)<n_(M)<n_(B),where n_(T) is the effective index of refraction of the top dielectricportion T, n_(M) is the effective index of refraction of the middledielectric portion M, and n_(B) is the effective index of refraction ofthe bottom dielectric portion B. Each of the top, middle and bottomdielectric portions T, M and B, respectively, can include a plurality ofdifferent dielectric layers, although in alternative embodiments any orall of these portions need only include a single dielectric layer. Bygradually decreasing the respective effective indices of refraction “n”from the innermost or bottom dielectric portion B, to the middledielectric portion M, and on to the top dielectric portion T toward theair, the anti-reflection system of this embodiment enables increasedvisible transmission to be achieved. Surprisingly, the anti-reflectionsystem may also enable fairly neutral color of the coated article incertain example embodiments.

EXAMPLE(S) OF FIG. 4 EMBODIMENT

The Tables below illustrate Examples 1–4 of the FIG. 4 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. Thus, the CE relates to a coating that is similarto that illustrated in the Ser. No. 09/794,224 application. Thethicknesses for each of the layers in the First Table below are inangstroms (Å). The Second Table below sets forth the opticalcharacteristics (e.g., visible transmission, color, etc.) for Examples1–4 and the CE based upon being annealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 4 embodiment) Glass CEEx. 1 Ex. 2 Ex. 3 Ex. 4 TiO₂ 125 Å 125 Å 269 Å 230 Å 125 Å Si₃N₄ 165 Å199 Å 54 Å 60 Å 198 Å NiCrO_(x) 18 Å 18 Å 18 Å 18 Å 18 Å Ag 98 Å 98 Å 98Å 98 Å 98 Å NiCrO_(x) 16 Å 16 Å 16 Å 16 Å 16 Å TiO₂ 0 Å 481 Å 219 Å 120Å 120 Å SnO₂ 672 Å 113 Å 710 Å 837 Å 782 Å Si₃N₄ 165 Å 0 Å 0 Å 0 Å 0 ÅNiCrO_(x) 18 Å 18 Å 18 Å 18 Å 18 Å Ag 98 Å 98 Å 98 Å 98 Å 98 Å NiCrO_(x)16 Å 16 Å 16 Å 16 Å 16 Å TiO₂ 0 Å 210 Å 181 Å 190 Å 190 Å SnO₂ 227 Å 34Å 32 Å 32 Å 10 Å Si₃N₄ 252 Å 0 Å 0 Å 0 Å 0 Å SiO_(x)N_(y) 0 Å 0 Å 0 Å 0Å 0 Å SiO₂ 0 Å 404 Å 334 Å 373 Å 435 Å Total diel: 1606 Å 1566 Å 1799 Å1842 Å 1860 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 4 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.3% −1.5 −0.1 5.0% 9.1 −7.1 3.9% 3.8 −2.4 Ex. 2:78.2% −1.7 0.9 4.5% 7.6 −11.9 4.1% 0.6 −3.5 Ex. 3: 78.1% −1.6 0.6 4.5%5.1 −9.4 4.0% 2.3 −3.0 Ex. 4: 77.8% −2.1 1.2 4.5% 9.2 −12.4 3.9% 3.9−2.4 CE: 75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 4 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Examples 1–4 (see FIG. 4) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1). Fairlyneutral color was also achieved in the Example(s).

FIG. 5 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 5 embodiment differs fromthe FIG. 3 embodiment in that an additional silicon nitride layer hasbeen added in the bottom dielectric portion B between the lower contactlayer and the titanium oxide layer, and a silicon oxide layer has beenadded over the silicon nitride layer in the top dielectric portion T.The coated article of FIG. 5 includes from the glass substrate outwardly(all indices n at 550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   silicon nitride (e.g., Si₃N₄) (n=1;8 to 2.0, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the silicon oxide, tin oxide, titanium oxide and siliconnitride dielectric layers as shown in this embodiment, the layer systemcan be characterized by the top dielectric portion T having an effectiveindex of refraction n less than that of middle dielectric portion M,which in turn has an effective index of refraction n less than or equalto that of the bottom dielectric portion B. In other words,n_(T)<n_(M)<=n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T, n_(M) is the effective index of refractionof the middle dielectric portion M, and n_(B) is the effective index ofrefraction of the bottom dielectric portion B. Each of the top, middleand bottom dielectric portions T, M and B, respectively, can include aplurality of different dielectric layers, although in alternativeembodiments any or all of these portions need only include a singledielectric layer. By gradually decreasing the respective effectiveindices of refraction “n” from the innermost or bottom dielectricportion B, to the middle dielectric portion M, and on to the topdielectric portion T toward the air, the anti-reflection system of thisembodiment enables increased visible transmission to be achieved.Surprisingly, the anti-reflection system may also enable fairly neutralcolor of the coated article in certain example embodiments.

EXAMPLE(S) OF FIG. 5 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 5 embodiment, comparedto a Comparative Example(s) (CE) similar to FIG. 1 of the instantapplication. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 5 embodiment) Glass CEEx. 1 TiO₂ 125 Å 125 Å Si₃N₄ 165 Å 196 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 488 Å SnO₂ 672 Å 91 Å Si₃N₄ 165 Å 0 ÅNiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 0 Å SnO₂227 Å 0 Å Si₃N₄ 252 Å 379 Å SiO_(x)N_(y) 0 Å 0 Å SiO₂ 0 Å 147 Å Totaldiel: 1606 Å 1426 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 5 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.1% −1.5 0.0 5.0% 8.5 −6.7 3.8% 3.4 −2.5 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 5 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission This %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 5) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral transmissive and glassside reflective color than the CE.

FIG. 6 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 6 embodiment differs fromthe FIG. 2 embodiment in that the upper tin oxide layer in the portion Thas been removed from the FIG. 2 embodiment and an additional siliconnitride layer has been added in the bottom dielectric portion B betweenthe lower contact layer and the titanium oxide layer. The coated articleof FIG. 6 includes from the glass substrate outwardly (all indices n at550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO2) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the silicon oxide, tin oxide, titanium oxide and siliconnitride dielectric layers as shown in this embodiment, the layer systemcan be characterized by the top dielectric portion T having an effectiveindex of refraction n less than that of middle dielectric portion M,which in turn has an effective index of refraction n less than or equalto that of the bottom dielectric portion B. In other words,n_(T)<n_(M)<=n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T, n_(M) is the effective index of refractionof the middle dielectric portion M, and n_(B) is the effective index ofrefraction of the bottom dielectric portion B. Each of the top, middleand bottom dielectric portions T, M and B, respectively, can include aplurality of different dielectric layers, although in alternativeembodiments any or all of these portions need only include a singledielectric layer. By gradually decreasing the respective effectiveindices of refraction “n” from the innermost or bottom dielectricportion B, to the middle dielectric portion M, and on to the topdielectric portion T toward the air, the anti-reflection system of thisembodiment enables increased visible transmission to be achieved.Surprisingly, the anti-reflection system may also enable fairly neutralcolor of the coated article in certain example embodiments.

EXAMPLE(S) OF FIG. 6 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 6 embodiment, comparedto a Comparative Example(s) (CE) similar to FIG. 1 of the instantapplication. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 6 embodiment) Glass CEEx. 1 TiO₂ 125 Å 125 Å Si₃N₄ 165 Å 201 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 477 Å SnO₂ 672 Å 71 Å Si₃N₄ 165 Å 0 ÅNiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 195 Å SnO₂227 Å 0 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å 0 Å SiO₂ 0 Å 509 Å Totaldiel: 1606 Å 1578 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 6 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.1% −1.1 −0.3 4.9% 4.7 −2.6 3.4% 2.0 −4.7 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 6 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 6) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral transmissive and glassside reflective color than the CE.

FIG. 7 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 7 embodiment differs fromthe FIG. 2 embodiment in that the upper titanium oxide layer from theFIG. 2 embodiment in portion T has been removed, and an additionalsilicon nitride layer has been added in FIG. 7 in the bottom dielectricportion B between the lower contact layer and the titanium oxide layer.The coated article of FIG. 7 includes from the glass substrate outwardly(all indices n at 550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO2) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the silicon-oxide, tin oxide, titanium oxide and siliconnitride dielectric layers as shown in this embodiment, the layer systemcan be characterized by the top dielectric portion T having an effectiveindex of refraction n less than that of middle dielectric portion M,which in turn has an effective index of refraction n less than or equalto that of the bottom dielectric portion B. In other words,n_(T)<n_(M)<=n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T, n_(M) is the effective index of refractionof the middle dielectric portion M, and n_(B) is the effective index ofrefraction of the bottom dielectric portion B. Each of the top, middleand bottom dielectric portions T, M and B, respectively, can include aplurality of different dielectric layers, although in alternativeembodiments any or all of these portions need only include a singledielectric layer. By gradually decreasing the respective effectiveindices of refraction “n” from the innermost or bottom dielectricportion B, to the middle dielectric portion M, and on to the topdielectric portion T toward the air, the anti-reflection system of thisembodiment enables increased visible transmission to be achieved.Surprisingly, the anti-reflection system may also enable fairly neutralcolor of the coated article in certain example embodiments.

EXAMPLE(S) OF FIG. 7 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 7 embodiment, comparedto a Comparative Example(s) (CE) similar to FIG. 1 of the instantapplication. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 7 embodiment) Glass CEEx. 1 TiO₂ 125 Å 125 Å Si₃N₄ 165 Å 220 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 171 Å SnO₂ 672 Å 690 Å Si₃N₄ 165 Å 0 ÅNiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 0 Å SnO₂227 Å 307 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å 0 Å SiO₂ 0 Å 222 Å Totaldiel: 1606 Å 1735 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 7 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 77.7% −2.1 1.5 4.5% 10.0 −13.7 3.7% 3.0 −2.7 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 7 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 7) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had fairly neutral color.

FIG. 8 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 8 embodiment differs fromthe FIG. 4 embodiment in that the upper dielectric portion in the FIG. 8embodiment includes a silicon oxynitride layer. The silicon oxynitridelayer is beneficial in that its index of refraction n (at 550 nm) can bevaried from 1.45 to 2.0, more preferably from 1.6 to 1.9, and mostpreferably from 1.65 to 1.85, in different embodiments of thisinvention. In this and all other silicon oxynitride inclusiveembodiments herein, the silicon oxynitride layer may have a constant (orapproximately constant, i.e., constant plus/minus about 5%) index ofrefraction n throughout its entire thickness in certain embodiments ofthis invention, but alternatively may be oxidation and/or nitride gradedso as to have an index of refraction n which varies through thethickness of the layer (e.g., the index n may gradually decrease throughthe thickness of the silicon oxynitride layer moving toward the air).The coated article of FIG. 8 includes from the glass substrate outwardly(all indices n at 550 nm):

-   -   glass (n=1.51)    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   titanium oxide (e.g., TiO₂) (n=2.1 to 2.7, preferably n=2.4 to        2.65)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon oxynitride (e.g., SiO_(x)N_(y)) (n=1.45–2.0, preferably        n=1.6–1.9)    -   air (n=1.0)

By using the silicon oxynitride, tin oxide, titanium oxide and siliconnitride dielectric layers as shown in this embodiment, the layer systemcan be characterized by the top dielectric portion T having an effectiveindex of refraction n (e.g., n=1.72 at 550 nm, as an example of an indexn of silicon oxynitride) less than that of middle dielectric portion M,which in turn has an effective index of refraction n less than or equalto that of the bottom dielectric portion B. In other words,n_(T)<n_(M)<=n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T, n_(M) is the effective index of refractionof the middle dielectric portion M, and n_(B) is the effective index ofrefraction of the bottom dielectric portion B. Each of the top, middleand bottom dielectric portions T, M and B, respectively, can include aplurality of different dielectric layers, although in alternativeembodiments any or all of these portions need only include a singledielectric layer. By gradually decreasing the respective effectiveindices of refraction “n” from the innermost or bottom dielectricportion B, to the middle dielectric portion M, and on to the topdielectric portion T toward the air (not including the Ag or contactlayers), the anti-reflection system of this embodiment enables increasedvisible transmission to be achieved. Surprisingly, the anti-reflectionsystem may also enable fairly neutral color of the coated article incertain example embodiments.

EXAMPLE(S) OF FIG. 8 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 8 embodiment, comparedto a Comparative Example(s) (CE) similar to FIG. 1 of the instantapplication. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 8 embodiment) Glass CEEx. 1 TiO₂ 125 Å 125 Å Si₃N₄ 165 Å 173 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 144 Å SnO₂ 672 Å 665 Å Si₃N₄ 165 Å 0 ÅNiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å TiO₂ 0 Å 0 Å SnO₂227 Å 0 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å 503 Å SiO₂ 0 Å 0 Å Totaldiel: 1606 Å 1610 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 8 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 76.8% −1.6 0.9 4.8% 3.1 −6.5 3.4% 3.7 −2.8 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 8 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 8) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral glass side reflectivecolor than the CE.

FIG. 9 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 9 embodiment differs fromFIG. 1 in that (a) the bottom titanium oxide and silicon nitride layersin bottom portion B of FIG. 1 have been removed and replaced with alayer of or including silicon zirconium nitride (SiZrN), (b) the siliconnitride layer in the middle portion M of FIG. 1 has been removed, (c) alayer of or including silicon zirconium nitride has been added to themiddle dielectric portion M in FIG. 9, and (d) the top silicon nitridelayer in top portion T in FIG. 1 has been replaced with a layer of orincluding silicon oxide in FIG. 9. It is noted that the siliconzirconium nitride inclusive layers may be stoichiometric ornon-stoichiometric in different embodiments of this invention. Moreover,one or more of the silicon zirconium nitride (SiZrN) layers may beoxided, and/or may be replaced with layer(s) comprising niobium oxide(e.g., Nb₂O₅ or any other suitable form). It is also noted that any ofthe tin oxide layers in portion(s) T and/or M could be replaced withsilicon nitride (e.g., stoichiometric or non-stoichiometric). The coatedarticle of FIG. 9 includes from the glass substrate outwardly (allindices n at 550 nm):

-   -   glass (n=1.51)    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the silicon zirconium nitride, silicon oxide, and tin oxidedielectric layers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 9 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 9 embodiment, comparedto a Comparative Example(s) (CE) similar to FIG. 1 of the instantapplication. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 9 embodiment) Glass CEEx. 1 SiZrN_(x) 0 Å 352 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å SiZrN_(x) 0 Å 232 Å SnO₂ 672 Å 680Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 ÅSiZrN_(x) 0 Å 125 Å SnO₂ 227 Å 143 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å 0Å SiO₂ 0 Å 327 Å Total diel: 1606 Å 1859 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 9 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 77.4% −2.8 3.1 4.4% 7.8 −11.5 3.8% 3.3 −2.7 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 9 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 9) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had fairly neutral color.

FIG. 10 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 10 embodiment differsfrom the FIG. 9 embodiment in that the upper silicon oxide and SiZrNinclusive layers in the top dielectric portion T have been removed. Itis noted that the silicon zirconium nitride inclusive layers may bestoichiometric or non-stoichiometric in different embodiments of thisinvention. Moreover, one or more of the silicon zirconium nitride(SiZrN) layers may be oxided, and/or may be replaced with layer(s)comprising niobium oxide (e.g., Nb₂O₅ or any other suitable form). Thecoated article of FIG. 10 includes from the glass substrate outwardly(all indices n at 550 nm):

-   -   glass (n=1.51)    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   tin oxide (e.g., SnO2) (n=1.8 to 2.2, preferably n=2.0)    -   air (n=1.0)

By using the silicon zirconium nitride, silicon oxide, and tin oxidedielectric layers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 10 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 10 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 10 embodiment) Glass CEEx. 1 SiZrN_(x) 0 Å 360 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å SiZrN_(x) 0 Å 240 Å SnO₂ 672 Å 667Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 ÅSiZrN_(x) 0 Å 0 Å SnO₂ 227 Å 399 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å 0 ÅSiO₂ 0 Å 0 Å Total diel: 1606 Å 1666 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 10 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 77.3% −2.9 3.8 4.5% 9.2 −12.6 4.1% 3.2 −2.9 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 10 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 10) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had fairly neutral transmissive color.

FIG. 11 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 11 embodiment differsfrom the FIG. 10 embodiment in that the upper and middle tin oxidelayers from FIG. 10 are replaced with respective layers of or includingsilicon nitride (stoichiometric or non-stoichiometric). It is noted thatthe silicon zirconium nitride inclusive layers may be stoichiometric ornon-stoichiometric in different embodiments of this invention. Moreover,one or more of the silicon zirconium nitride (SiZrN) layers may beoxided, and/or may be replaced with layer(s) comprising niobium oxide(e.g., Nb₂O₅ or any other suitable form). The coated article of FIG. 11includes from the glass substrate outwardly (all indices n at 550 nm):

-   -   glass (n=1.51)    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon zirconium nitride (SiZrN_(x)) (n=2.2–2.45, preferably        n=2.32)    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   air (n=1.0)

By using the silicon zirconium nitride and silicon nitride dielectriclayers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 11 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 11 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 11 embodiment) Glass CEEx. 1 SiZrN_(x) 0 Å 360 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å SiZrN_(x) 0 Å 229 Å SnO₂ 672 Å 0 ÅSi₃N₄ 165 Å 684 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 ÅSiZrN_(x) 0 Å 0 Å SnO₂ 227 Å 0 Å Si₃N₄ 252 Å 404 Å SiO_(x)N_(y) 0 Å 0 ÅSiO₂ 0 Å 0 Å Total diel: 1606 Å 1677 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 11 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 77.3% −2.6 3.4 4.5% 9.0 −12.3 4.1% 3.9 −2.7 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 11 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 11) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had fairly neutral color.

FIG. 12 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 12 embodiment differsfrom FIG. 1 in that (a) the bottom titanium oxide and silicon nitridelayers in bottom portion B of FIG. 1 have been removed and replaced witha layer of or including niobium oxide (stoichiometric Nb₂O₅, or somenon-stoichiometic form), (b) the silicon nitride layer in the middleportion M of FIG. 1 has been removed, (c) a layer of or includingniobium oxide (stoichiometric Nb₂O₅, or some non-stoichiometic form) hasbeen added to the middle dielectric portion M in FIG. 12, and (d) thetop silicon nitride layer in top portion T in FIG. 1 has been replacedwith a layer of or including silicon oxide (stoichiometric ornon-stoichiometric) in FIG. 12. The coated article of FIG. 12 includesfrom the glass substrate outwardly (all indices n at 550 nm):

-   -   glass (n=1.51)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the niobium oxide, silicon oxide, and tin oxide dielectriclayers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 12 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 12 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 12 embodiment) Glass CEEx. 1 Nb_(x)O_(y) 0 Å 342 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å Nb_(x)O_(y) 0 Å 640 Å SnO₂ 672 Å96 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16Å Nb_(x)O_(y) 0 Å 222 Å SnO₂ 227 Å 37 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å0 Å SiO₂ 0 Å 372 Å Total diel: 1606 Å 1709 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 12 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.5% −1.3 −0.3 4.6% 8.2 −8.6 4.0% 3.7 −2.4 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 12 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 12) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral transmissive and glassside reflective color than the CE.

FIG. 13 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 13 embodiment differsfrom the FIG. 12 embodiment in that the top silicon oxide and niobiumoxide layers in top dielectric portion T of FIG. 12 have been removed.The coated article of FIG. 13 includes from the glass substrateoutwardly (all indices n at 550 nm):

-   -   glass (n=1.51)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   air (n=1.0)

By using the niobium oxide and tin oxide dielectric layers as shown inthis embodiment, the layer system can be characterized by the topdielectric portion T having an effective index of refraction n less thanthat of middle dielectric portion M, which in turn has an effectiveindex of refraction n less than that of the bottom dielectric portion B.In other words, n_(T)<n_(M)<n_(B), where n_(T) is the effective index ofrefraction of the top dielectric portion T, n_(M) is the effective indexof refraction of the middle dielectric portion M, and n_(B) is theeffective index of refraction of the bottom dielectric portion B. Eachof the top, middle and bottom dielectric portions T, M and B,respectively, can include a plurality of different dielectric layers,although in alternative embodiments any or all of these portions needonly include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 13 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 13 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 13 embodiment) Glass CEEx. 1 Nb_(x)O_(y) 0 Å 347 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å Nb_(x)O_(y) 0 Å 639 Å SnO₂ 672 Å90 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16Å Nb_(x)O_(y) 0 Å 0 Å SnO₂ 227 Å 428 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å0 Å SiO₂ 0 Å 0 Å Total diel: 1606 Å 1504 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 13 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.4% −1.5 0.1 4.6% 9.0 −9.9 4.1% 3.2 −2.6 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 13 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 13) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral transmissive and glassside reflective color than the CE.

FIG. 14 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 14 embodiment differsfrom the FIG. 13 embodiment in that the top tin oxide layer of FIG. 13has been replaced with a silicon nitride inclusive layer in FIG. 14. Thecoated article of FIG. 14 includes from the glass substrate outwardly(all indices n at 550 nm):

-   -   glass (n=1.51)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium-oxide (NiCrO_(x))    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   air (n=1.0)

By using the niobium oxide, silicon nitride, and tin oxide dielectriclayers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 14 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 14 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 14 embodiment) Glass CEEx. 1 Nb_(x)O_(y) 0 Å 344 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16 Å Nb_(x)O_(y) 0 Å 641 Å SnO₂ 672 Å89 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 16Å Nb_(x)O_(y) 0 Å 0 Å SnO₂ 227 Å 0 Å Si₃N₄ 252 Å 428 Å SiO_(x)N_(y) 0 Å0 Å SiO₂ 0 Å 0 Å Total diel: 1606 Å 1502 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 14 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 78.3% −1.4 0.0 4.6% 8.7 −9.3 4.1% 3.4 −2.5 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 14 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 14) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral transmissive and glassside reflective color than the CE.

FIG. 15 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 15 embodiment differsfrom the FIG. 12 embodiment in that the two upper nickel chrome oxidecontact layers have been removed from the FIG. 12 embodiment. The coatedarticle of FIG. 15 includes from the glass substrate outwardly (allindices n at 550 nm):

-   -   glass (n=1.51)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   silicon oxide (e.g., SiO₂) (n=1.4 to 1.7, preferably n=1.45)    -   air (n=1.0)

By using the niobium oxide, silicon oxide, and tin oxide dielectriclayers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments.

EXAMPLE(S) OF FIG. 15 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 15 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 15 embodiment) Glass CEEx. 1 Nb_(x)O_(y) 0 Å 337 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 0 Å Nb_(x)O_(y) 0 Å 564 Å SnO₂ 672 Å169 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 0Å Nb_(x)O_(y) 0 Å 209 Å SnO₂ 227 Å 50 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å0 Å SiO₂ 0 Å 379 Å Total diel: 1606 Å 1708 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 15 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 82.1% −1.1 −0.8 4.5% 4.0 −3.9 3.8% 1.4 −1.8 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 15 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 15) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral color than the CE.

FIG. 16 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 16 embodiment differsfrom the FIG. 15 embodiment in that the upper silicon oxide and tinoxide layers in top dielectric portion T have been replaced with a layerof or including silicon oxynitride. The coated article of FIG. 16includes from the glass substrate outwardly (all indices n at 550 nm):

-   -   glass (n=1.51)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   silicon oxynitride (e.g., SiO_(x)N_(y)) (n=1.45–2.0, preferably        n=1.6–1.9)    -   air (n=1.0)

By using the niobium oxide, silicon oxynitride, and tin oxide dielectriclayers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than that of middle dielectric portion M, which inturn has an effective index of refraction n less than that of the bottomdielectric portion B. In other words, n_(T)<n_(M)<n_(B), where n_(T) isthe effective index of refraction of the top dielectric portion T, n_(M)is the effective index of refraction of the middle dielectric portion M,and n_(B) is the effective index of refraction of the bottom dielectricportion B. Each of the top, middle and bottom dielectric portions T, Mand B, respectively, can include a plurality of different dielectriclayers, although in alternative embodiments any or all of these portionsneed only include a single dielectric layer. By gradually decreasing therespective effective indices of refraction “n” from the innermost orbottom dielectric portion B, to the middle dielectric portion M, and onto the top dielectric portion T toward the air, the anti-reflectionsystem of this embodiment enables increased visible transmission to beachieved. Surprisingly, the anti-reflection system may also enablefairly neutral color of the coated article in certain exampleembodiments. The silicon oxynitride layer is beneficial in that itsindex of refraction n (at 550 nm) can be varied from 1.45 to 2.0, morepreferably from 1.6 to 1.9, and most preferably from 1.65 to 1.85, indifferent embodiments of this invention. In this and all other siliconoxynitride inclusive embodiments herein, the silicon oxynitride layermay have a constant (or approximately constant, i.e., constantplus/minus about 5%) index of refraction n throughout its entirethickness in certain embodiments of this invention, but alternativelymay be oxidation and/or nitride graded so as to have an index ofrefraction n which varies through the thickness of the layer (e.g., theindex n may gradually decrease through the thickness of the siliconoxynitride layer moving toward the air).

EXAMPLE(S) OF FIG. 16 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 16 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 16 embodiment) Glass CEEx. 1 Nb_(x)O_(y) 0 Å 342 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 0 Å Nb_(x)O_(y) 0 Å 554 Å SnO₂ 672 Å188 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 0Å Nb_(x)O_(y) 0 Å 182 Å SnO₂ 227 Å 0 Å Si₃N₄ 252 Å 0 Å SiO_(x)N_(y) 0 Å336 Å SiO₂ 0 Å 0 Å Total diel: 1606 Å 1602 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 16 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 82.0% −1.1 −0.7 4.6% 4.5 −4.6 3.9% 1.5 −1.8 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 16 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 16) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1).Surprisingly, Example 1 also had more neutral color than the CE(especially glass side reflective color).

FIG. 17 is a cross sectional view of a coated article according toanother embodiment of this invention. The FIG. 17 embodiment differsfrom the FIG. 14 embodiment in that an additional niobium oxide layerhas been added to the top dielectric portion T, and the two top contactlayers were NiCr (i.e. not significantly oxided). The coated article ofFIG. 17 includes from the glass substrate outwardly (all indices n at550 nm):

-   -   glass (n=1.51)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium (NiCr)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   tin oxide (e.g., SnO₂) (n=1.8 to 2.2, preferably n=2.0)    -   nickel-chromium-oxide (NiCrO_(x))    -   silver (Ag)    -   nickel-chromium (NiCr)    -   niobium oxide (e.g., Nb₂O₅) (n=2.25–2.5, preferably n=2.33)    -   silicon nitride (e.g., Si₃N₄) (n=1.8 to 2.0, preferably n=2.0)    -   air (n=1.0)

By using the niobium oxide, silicon nitride, and tin oxide dielectriclayers as shown in this embodiment, the layer system can becharacterized by the top dielectric portion T having an effective indexof refraction n less than or equal to that of middle dielectric portionM, which in turn has an effective index of refraction n less than orequal to that of the bottom dielectric portion B. In other words,n_(T)<=n_(M)<=n_(B), where n_(T) is the effective index of refraction ofthe top dielectric portion T, n_(M) is the effective index of refractionof the middle dielectric portion M, and n_(B) is the effective index ofrefraction of the bottom dielectric portion B. Each of the top, middleand bottom dielectric portions T, M and B, respectively, can include aplurality of different dielectric layers, although in alternativeembodiments any or all of these portions need only include a singledielectric layer. By gradually decreasing the respective effectiveindices of refraction “n” from the innermost or bottom dielectricportion B, to the middle dielectric portion M, and on to the topdielectric portion T toward the air, the anti-reflection system of thisembodiment enables increased visible transmission to be achieved.Surprisingly, the anti-reflection system may also enable fairly neutralcolor of the coated article in certain example embodiments. While thetwo upper contact layers were NiCr (not significantly oxided) in thisembodiment, it will be recognized by those skilled in the art that inother embodiments of this invention these NiCr contact layers may benitrided.

EXAMPLE(S) OF FIG. 17 EMBODIMENT

The Tables below illustrate Example 1 of the FIG. 17 embodiment,compared to a Comparative Example(s) (CE) similar to FIG. 1 of theinstant application. The CE relates to a coating that is similar to thatillustrated in the Ser. No. 09/794,224 application. The thicknesses foreach of the layers in the First Table below are in angstroms (Å). TheSecond Table below sets forth the optical characteristics (e.g., visibletransmission, color, etc.) for Example 1 and the CE based upon beingannealed and in monolithic form.

FIRST TABLE: LAYER STRUCTURE - thicknesses (FIG. 17 embodiment) Glass CEEx. 1 Nb_(x)O_(y) 0 Å 346 Å TiO₂ 125 Å 0 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18Å 18 Å Ag 98 Å 98 Å NiCrO_(x) 16 Å 0 Å NiCr 0 Å 3 Å Nb_(x)O_(y) 0 Å 652Å SnO₂ 672 Å 108 Å Si₃N₄ 165 Å 0 Å NiCrO_(x) 18 Å 18 Å Ag 98 Å 98 ÅNiCrO_(x) 16 Å 0 Å NiCr 0 Å 3 Å Nb_(x)O_(y) 0 Å 88 Å SnO₂ 227 Å 0 ÅSi₃N₄ 252 Å 350 Å SiO_(X)N_(y) 0 Å 0 Å SiO₂ 0 Å 0 Å Total diel: 1606 Å1544 Å

SECOND TABLE: OPTICAL PERFORMANCE (FIG. 17 embodiment; monolithic)T_(vis) a*_(t) b*_(t) R_(glass side (g)) a*_(g) b*_(g) R_(film side (f))a*_(f) b*_(f) Ex. 1: 77.3% −1.8 −0.8 4.7% 10.3 −10.7 4.4% 4.1 −2.8 CE:75.5% −2.1 0.2 5.9% 9.2 −10.6 5.2% 3.2 −1.0

It can be seen from the Tables above regarding the FIG. 17 embodiment ofthis invention, that the anti-reflection system of the instant inventionenables not only better visible transmission characteristics (i.e.,increased visible transmission T_(vis) %), but also reduced reflection(e.g., lower glass side reflection and/or film side visible reflection).In particular, Example 1 (see FIG. 17) had better visible transmission(higher T_(vis)) and better glass and/or film side reflection (lowerR_(g) and/or R_(f)) than the Comparative Example (CE—see FIG. 1). Fairlyneutral transmissive color was also provided in Example 1.

Accordingly, coated articles of certain example embodiments of thisinvention are characterized by one or more of the following parameters:

Characteristic General More Preferred Most Preferred T_(vis) (Ill. C. 2deg.): >=70% >=75% >=76.5%  R_(g)Y (Ill. C., 2 deg.): <=11%  <=9% <=5.0%R_(f)Y (Ill. C.; 2 deg.): <=11%  <=9% <=5.0% T_(solar): <=50% <=48%

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims. For example and without limitation,materials other than those described above may be used in otherembodiments of this invention without departing from the spirit of thisinvention. For example and without limitation, silicon oxide layers maybe at least partially nitrided in certain embodiments, and siliconnitride layers may be at least partially oxided in certain embodiments.

1. A coated article including a coating supported by a glass substrate,the coating comprising, from the glass substrate outwardly: a firstdielectric layer comprising silicon zirconium nitride; a first contactlayer comprising NiCr; a first IR reflecting layer comprising Ag; asecond contact layer comprising NiCr; a second dielectric layercomprising silicon zirconium nitride; a third dielectric layer having anindex of refraction n less than an index of refraction n of at least oneof the first and second dielectric layers; a third contact layercomprising NiCr; a second IR reflecting layer comprising Ag; a fourthcontact layer comprising NiCr; a fourth dielectric layer comprisingsilicon oxide; and wherein the coated article has a visible transmissionof at least 70% and a sheet resistance (R_(s)) of no greater than 10ohms/square.
 2. The coated article of claim 1, wherein the coatedarticle has a visible transmission of at least 75%.
 3. The coatedarticle of claim 1, wherein the third dielectric layer comprises tinoxide.
 4. The coated article of claim 3, wherein the coated article hasa visible transmission of at least 76.5%.
 5. The coated article of claim1, further comprising another dielectric layer comprising tin oxideprovided between the fourth dielectric layer comprising silicon oxideand the fourth contact layer.
 6. The coated article of claim 5, furthercomprising another dielectric layer comprising silicon zirconium nitrideprovided between the fourth dielectric layer comprising silicon oxideand the second IR reflecting layer, the another dielectric layercomprising silicon zirconium nitride being provided under the anotherdielectric layer comprising tin oxide.
 7. A coated article including acoating supported by a glass substrate, the coating comprising, from theglass substrate outwardly: a first dielectric layer comprising siliconzirconium nitride; a contact layer; a first IR reflecting layercomprising Ag; a second dielectric layer comprising silicon zirconiumnitride; a third dielectric layer having an index of refraction n lessthan an index of refraction of at least one of the first and seconddielectric layers; a contact layer, at least one of the contact layerscomprising an oxide and/or nitride of NiCr; a second IR reflecting layercomprising Ag; a fourth dielectric layer comprising at least one of tinoxide and silicon nitride; and wherein the coated article has a visibletransmission of at least 70% and a sheet resistance (R_(s)) of nogreater than 10 ohms/square.
 8. The coated article of claim 7, whereinthe third dielectric layer comprises one of silicon nitride and tinoxide.
 9. The coated article of claim 7, wherein the coated article hasa visible transmission of at least 75%.
 10. A coated article including acoating supported by a glass substrate, the coating comprising: firstand second infrared (IR) reflecting layers each comprising at least oneof Ag and Au; a first dielectric portion having an effective index ofrefraction n₁<=3.0 provided between the first IR reflecting layer andthe glass substrate; a second dielectric portion having an effectiveindex of refraction n₂ less than or equal to n₁, the second dielectricportion provided between the first and second IR reflecting layers; athird dielectric portion provided over the first and second IRreflecting layers, said third dielectric layer having an effective indexof refraction n₃ less than n₁ and n₂, so that n₃<n₂<=n₁; wherein thecoated article has a visible transmission of at least 70%; and whereinthe third dielectric portion comprises a layer comprising siliconzirconium nitride and a layer comprising silicon oxide.
 11. A coatedarticle including a coating supported by a glass substrate, the coatingcomprising: first and second infrared (IR) reflecting layers eachcomprising at least one of Ag and Au; a first dielectric portion havingan effective index of refraction n₁<=3.0 provided between the first IRreflecting layer and the glass substrate; a second dielectric portionhaving an effective index of refraction n₂ less than or equal to n₁, thesecond dielectric portion provided between the first and second IRreflecting layers; a third dielectric portion provided over the firstand second IR reflecting layers, said third dielectric layer having aneffective index of refraction n₃ less than n₁ and n₂, so that n₃<n₂<=n₁;wherein the coated article has a visible transmission of at least 70%;and wherein the second dielectric portion comprises a layer comprisingtin oxide and a layer comprising one of niobium oxide and siliconzirconium nitride.